diff --git a/packages/opencode/src/provider/provider.ts b/packages/opencode/src/provider/provider.ts
index a02a017e77c..f3d965654f1 100644
--- a/packages/opencode/src/provider/provider.ts
+++ b/packages/opencode/src/provider/provider.ts
@@ -961,6 +961,21 @@ export namespace Provider {
             (v) => omit(v, ["disabled"]),
           )
         }
+
+        // Auto-detect 1M context window for Claude models when the user
+        // configures the context-1m beta flag. Without this, models.dev reports
+        // 200k and compaction triggers too early.
+        // Bedrock uses providerOptions: anthropicBeta (array of strings).
+        // Anthropic direct uses HTTP headers: anthropic-beta (comma-separated string).
+        if (model.limit.context <= 200_000) {
+          const has1mBeta =
+            (Array.isArray(model.options?.anthropicBeta) &&
+              model.options.anthropicBeta.some((b: string) => /^context-1m-/.test(b))) ||
+            /context-1m-/.test(model.headers?.["anthropic-beta"] ?? "")
+          if (has1mBeta) {
+            model.limit = { ...model.limit, context: 1_000_000 }
+          }
+        }
       }
 
       if (Object.keys(provider.models).length === 0) {
diff --git a/packages/opencode/src/provider/transform.ts b/packages/opencode/src/provider/transform.ts
index 7ed89cb2599..c5c699b8ec4 100644
--- a/packages/opencode/src/provider/transform.ts
+++ b/packages/opencode/src/provider/transform.ts
@@ -20,6 +20,14 @@ function mimeToModality(mime: string): Modality | undefined {
 export namespace ProviderTransform {
   export const OUTPUT_TOKEN_MAX = Flag.OPENCODE_EXPERIMENTAL_OUTPUT_TOKEN_MAX || 32_000
 
+  // Returns true if the model is a Claude model on any provider (Anthropic, Bedrock, Vertex).
+  // Claude uniformly rejects empty content blocks regardless of host provider.
+  function isClaude(model: Provider.Model): boolean {
+    return (
+      model.api.npm === "@ai-sdk/anthropic" || model.api.id.includes("claude") || model.api.id.includes("anthropic")
+    )
+  }
+
   // Maps npm package to the key the AI SDK expects for providerOptions
   function sdkKey(npm: string): string | undefined {
     switch (npm) {
@@ -49,9 +57,10 @@ export namespace ProviderTransform {
     model: Provider.Model,
     options: Record<string, unknown>,
   ): ModelMessage[] {
-    // Anthropic rejects messages with empty content - filter out empty string messages
-    // and remove empty text/reasoning parts from array content
-    if (model.api.npm === "@ai-sdk/anthropic") {
+    // Claude rejects messages with empty content - filter out empty string messages
+    // and remove empty text/reasoning parts from array content.
+    // This applies to all providers hosting Claude models (Anthropic, Bedrock, Vertex).
+    if (isClaude(model)) {
       msgs = msgs
         .map((msg) => {
           if (typeof msg.content === "string") {
diff --git a/packages/opencode/src/session/compaction.ts b/packages/opencode/src/session/compaction.ts
index 5660ca97319..2b2fd899e01 100644
--- a/packages/opencode/src/session/compaction.ts
+++ b/packages/opencode/src/session/compaction.ts
@@ -183,7 +183,7 @@ When constructing the summary, try to stick to this template:
       tools: {},
       system: [],
       messages: [
-        ...MessageV2.toModelMessages(input.messages, model),
+        ...MessageV2.toModelMessages(input.messages, model, { stripMetadata: true }),
         {
           role: "user",
           content: [
diff --git a/packages/opencode/src/session/message-v2.ts b/packages/opencode/src/session/message-v2.ts
index 63159ecc50c..894a514ac7f 100644
--- a/packages/opencode/src/session/message-v2.ts
+++ b/packages/opencode/src/session/message-v2.ts
@@ -442,7 +442,11 @@ export namespace MessageV2 {
   })
   export type WithParts = z.infer<typeof WithParts>
 
-  export function toModelMessages(input: WithParts[], model: Provider.Model): ModelMessage[] {
+  export function toModelMessages(
+    input: WithParts[],
+    model: Provider.Model,
+    options?: { stripMetadata?: boolean },
+  ): ModelMessage[] {
     const result: UIMessage[] = []
     const toolNames = new Set<string>()
     // Track media from tool results that need to be injected as user messages
@@ -540,7 +544,8 @@ export namespace MessageV2 {
       }
 
       if (msg.info.role === "assistant") {
-        const differentModel = `${model.providerID}/${model.id}` !== `${msg.info.providerID}/${msg.info.modelID}`
+        const skipMetadata =
+          options?.stripMetadata || `${model.providerID}/${model.id}` !== `${msg.info.providerID}/${msg.info.modelID}`
         const media: Array<{ mime: string; url: string }> = []
 
         if (
@@ -562,7 +567,7 @@ export namespace MessageV2 {
             assistantMessage.parts.push({
               type: "text",
               text: part.text,
-              ...(differentModel ? {} : { providerMetadata: part.metadata }),
+              ...(skipMetadata ? {} : { providerMetadata: part.metadata }),
             })
           if (part.type === "step-start")
             assistantMessage.parts.push({
@@ -599,7 +604,7 @@ export namespace MessageV2 {
                 toolCallId: part.callID,
                 input: part.state.input,
                 output,
-                ...(differentModel ? {} : { callProviderMetadata: part.metadata }),
+                ...(skipMetadata ? {} : { callProviderMetadata: part.metadata }),
               })
             }
             if (part.state.status === "error")
@@ -609,7 +614,7 @@ export namespace MessageV2 {
                 toolCallId: part.callID,
                 input: part.state.input,
                 errorText: part.state.error,
-                ...(differentModel ? {} : { callProviderMetadata: part.metadata }),
+                ...(skipMetadata ? {} : { callProviderMetadata: part.metadata }),
               })
             // Handle pending/running tool calls to prevent dangling tool_use blocks
             // Anthropic/Claude APIs require every tool_use to have a corresponding tool_result
@@ -620,14 +625,14 @@ export namespace MessageV2 {
                 toolCallId: part.callID,
                 input: part.state.input,
                 errorText: "[Tool execution was interrupted]",
-                ...(differentModel ? {} : { callProviderMetadata: part.metadata }),
+                ...(skipMetadata ? {} : { callProviderMetadata: part.metadata }),
               })
           }
           if (part.type === "reasoning") {
             assistantMessage.parts.push({
               type: "reasoning",
               text: part.text,
-              ...(differentModel ? {} : { providerMetadata: part.metadata }),
+              ...(skipMetadata ? {} : { providerMetadata: part.metadata }),
             })
           }
         }
diff --git a/packages/opencode/test/provider/provider.test.ts b/packages/opencode/test/provider/provider.test.ts
index 98cd49c02fd..7602a6e455f 100644
--- a/packages/opencode/test/provider/provider.test.ts
+++ b/packages/opencode/test/provider/provider.test.ts
@@ -2127,3 +2127,111 @@ test("custom model with variants enabled and disabled", async () => {
     },
   })
 })
+
+test("bedrock model with anthropicBeta context-1m option gets 1M context limit", async () => {
+  await using tmp = await tmpdir({
+    init: async (dir) => {
+      await Bun.write(
+        path.join(dir, "opencode.json"),
+        JSON.stringify({
+          $schema: "https://opencode.ai/config.json",
+          provider: {
+            "amazon-bedrock": {
+              models: {
+                "us.anthropic.claude-opus-4-6-v1": {
+                  options: {
+                    anthropicBeta: ["context-1m-2025-08-07"],
+                  },
+                },
+              },
+            },
+          },
+        }),
+      )
+    },
+  })
+  await Instance.provide({
+    directory: tmp.path,
+    init: async () => {
+      Env.set("AWS_ACCESS_KEY_ID", "test")
+      Env.set("AWS_SECRET_ACCESS_KEY", "test")
+      Env.set("AWS_REGION", "us-east-1")
+    },
+    fn: async () => {
+      const providers = await Provider.list()
+      const model = providers["amazon-bedrock"]?.models["us.anthropic.claude-opus-4-6-v1"]
+      if (!model) return // skip if models.dev doesn't include this model in test env
+      expect(model.limit.context).toBe(1_000_000)
+    },
+  })
+})
+
+test("bedrock model without anthropicBeta keeps default context limit", async () => {
+  await using tmp = await tmpdir({
+    init: async (dir) => {
+      await Bun.write(
+        path.join(dir, "opencode.json"),
+        JSON.stringify({
+          $schema: "https://opencode.ai/config.json",
+          provider: {
+            "amazon-bedrock": {
+              models: {
+                "us.anthropic.claude-opus-4-6-v1": {},
+              },
+            },
+          },
+        }),
+      )
+    },
+  })
+  await Instance.provide({
+    directory: tmp.path,
+    init: async () => {
+      Env.set("AWS_ACCESS_KEY_ID", "test")
+      Env.set("AWS_SECRET_ACCESS_KEY", "test")
+      Env.set("AWS_REGION", "us-east-1")
+    },
+    fn: async () => {
+      const providers = await Provider.list()
+      const model = providers["amazon-bedrock"]?.models["us.anthropic.claude-opus-4-6-v1"]
+      if (!model) return
+      expect(model.limit.context).toBeLessThanOrEqual(200_000)
+    },
+  })
+})
+
+test("anthropic model with context-1m header gets 1M context limit", async () => {
+  await using tmp = await tmpdir({
+    init: async (dir) => {
+      await Bun.write(
+        path.join(dir, "opencode.json"),
+        JSON.stringify({
+          $schema: "https://opencode.ai/config.json",
+          provider: {
+            anthropic: {
+              models: {
+                "claude-opus-4-6": {
+                  headers: {
+                    "anthropic-beta": "context-1m-2025-08-07",
+                  },
+                },
+              },
+            },
+          },
+        }),
+      )
+    },
+  })
+  await Instance.provide({
+    directory: tmp.path,
+    init: async () => {
+      Env.set("ANTHROPIC_API_KEY", "test-key")
+    },
+    fn: async () => {
+      const providers = await Provider.list()
+      const model = providers["anthropic"]?.models["claude-opus-4-6"]
+      if (!model) return
+      expect(model.limit.context).toBe(1_000_000)
+    },
+  })
+})
diff --git a/packages/opencode/test/provider/transform.test.ts b/packages/opencode/test/provider/transform.test.ts
index 02bb5278fc7..64b3b7e3678 100644
--- a/packages/opencode/test/provider/transform.test.ts
+++ b/packages/opencode/test/provider/transform.test.ts
@@ -649,7 +649,7 @@ describe("ProviderTransform.message - empty image handling", () => {
   })
 })
 
-describe("ProviderTransform.message - anthropic empty content filtering", () => {
+describe("ProviderTransform.message - claude empty content filtering", () => {
   const anthropicModel = {
     id: "anthropic/claude-3-5-sonnet",
     providerID: "anthropic",
@@ -797,7 +797,7 @@ describe("ProviderTransform.message - anthropic empty content filtering", () =>
     expect(result[0].content[1]).toEqual({ type: "text", text: "Result" })
   })
 
-  test("does not filter for non-anthropic providers", () => {
+  test("does not filter for non-claude providers", () => {
     const openaiModel = {
       ...anthropicModel,
       providerID: "openai",
@@ -822,6 +822,66 @@ describe("ProviderTransform.message - anthropic empty content filtering", () =>
     expect(result[0].content).toBe("")
     expect(result[1].content).toHaveLength(1)
   })
+
+  test("filters empty content for bedrock claude models", () => {
+    const bedrockModel = {
+      ...anthropicModel,
+      providerID: "amazon-bedrock",
+      api: {
+        id: "us.anthropic.claude-opus-4-6-v1",
+        url: "https://bedrock-runtime.us-east-1.amazonaws.com",
+        npm: "@ai-sdk/amazon-bedrock",
+      },
+    }
+
+    const msgs = [
+      { role: "assistant", content: "" },
+      {
+        role: "assistant",
+        content: [
+          { type: "text", text: "" },
+          { type: "text", text: "Hello" },
+        ],
+      },
+      {
+        role: "assistant",
+        content: [
+          { type: "reasoning", text: "" },
+          { type: "text", text: "Answer" },
+        ],
+      },
+    ] as any[]
+
+    const result = ProviderTransform.message(msgs, bedrockModel, {})
+
+    expect(result).toHaveLength(2)
+    expect(result[0].content).toHaveLength(1)
+    expect(result[0].content[0]).toEqual({ type: "text", text: "Hello" })
+    expect(result[1].content).toHaveLength(1)
+    expect(result[1].content[0]).toEqual({ type: "text", text: "Answer" })
+  })
+
+  test("filters empty content for vertex claude models", () => {
+    const vertexModel = {
+      ...anthropicModel,
+      providerID: "google-vertex",
+      api: {
+        id: "claude-opus-4-6@20260205",
+        url: "https://us-east5-aiplatform.googleapis.com",
+        npm: "@ai-sdk/google-vertex",
+      },
+    }
+
+    const msgs = [
+      { role: "assistant", content: "" },
+      { role: "user", content: "World" },
+    ] as any[]
+
+    const result = ProviderTransform.message(msgs, vertexModel, {})
+
+    expect(result).toHaveLength(1)
+    expect(result[0].content).toBe("World")
+  })
 })
 
 describe("ProviderTransform.message - strip openai metadata when store=false", () => {
diff --git a/packages/opencode/test/session/message-v2.test.ts b/packages/opencode/test/session/message-v2.test.ts
index c043754bdb4..38433976622 100644
--- a/packages/opencode/test/session/message-v2.test.ts
+++ b/packages/opencode/test/session/message-v2.test.ts
@@ -784,6 +784,141 @@ describe("session.message-v2.toModelMessage", () => {
       },
     ])
   })
+
+  test("strips provider metadata when stripMetadata option is set", () => {
+    const userID = "m-user"
+    const assistantID = "m-assistant"
+
+    const input: MessageV2.WithParts[] = [
+      {
+        info: userInfo(userID),
+        parts: [
+          {
+            ...basePart(userID, "u1"),
+            type: "text",
+            text: "hello",
+          },
+        ] as MessageV2.Part[],
+      },
+      {
+        info: assistantInfo(assistantID, userID),
+        parts: [
+          {
+            ...basePart(assistantID, "a1"),
+            type: "text",
+            text: "response",
+            metadata: { bedrock: { thinking: "sig" } },
+          },
+          {
+            ...basePart(assistantID, "a2"),
+            type: "reasoning",
+            text: "thinking about it",
+            time: { start: 0 },
+            metadata: { bedrock: { thinking_signature: "abc" } },
+          },
+          {
+            ...basePart(assistantID, "a3"),
+            type: "tool",
+            callID: "call-1",
+            tool: "bash",
+            state: {
+              status: "completed",
+              input: { cmd: "ls" },
+              output: "ok",
+              title: "Bash",
+              metadata: {},
+              time: { start: 0, end: 1 },
+            },
+            metadata: { bedrock: { tool_meta: "xyz" } },
+          },
+        ] as MessageV2.Part[],
+      },
+    ]
+
+    // Same model, but stripMetadata=true should still omit metadata
+    const result = MessageV2.toModelMessages(input, model, { stripMetadata: true })
+
+    expect(result).toStrictEqual([
+      {
+        role: "user",
+        content: [{ type: "text", text: "hello" }],
+      },
+      {
+        role: "assistant",
+        content: [
+          { type: "text", text: "response" },
+          { type: "reasoning", text: "thinking about it", providerOptions: undefined },
+          {
+            type: "tool-call",
+            toolCallId: "call-1",
+            toolName: "bash",
+            input: { cmd: "ls" },
+            providerExecuted: undefined,
+          },
+        ],
+      },
+      {
+        role: "tool",
+        content: [
+          {
+            type: "tool-result",
+            toolCallId: "call-1",
+            toolName: "bash",
+            output: { type: "text", value: "ok" },
+          },
+        ],
+      },
+    ])
+  })
+
+  test("preserves provider metadata without stripMetadata option", () => {
+    const userID = "m-user"
+    const assistantID = "m-assistant"
+
+    const input: MessageV2.WithParts[] = [
+      {
+        info: userInfo(userID),
+        parts: [
+          {
+            ...basePart(userID, "u1"),
+            type: "text",
+            text: "hello",
+          },
+        ] as MessageV2.Part[],
+      },
+      {
+        info: assistantInfo(assistantID, userID),
+        parts: [
+          {
+            ...basePart(assistantID, "a1"),
+            type: "reasoning",
+            text: "thinking",
+            time: { start: 0 },
+            metadata: { bedrock: { sig: "keep" } },
+          },
+        ] as MessageV2.Part[],
+      },
+    ]
+
+    const result = MessageV2.toModelMessages(input, model)
+
+    expect(result).toStrictEqual([
+      {
+        role: "user",
+        content: [{ type: "text", text: "hello" }],
+      },
+      {
+        role: "assistant",
+        content: [
+          {
+            type: "reasoning",
+            text: "thinking",
+            providerOptions: { bedrock: { sig: "keep" } },
+          },
+        ],
+      },
+    ])
+  })
 })
 
 describe("session.message-v2.fromError", () => {